Pain is the most common symptom for which patients seek medical advice and treatment. Pain can be acute or chronic. While acute pain is usually self-limited, chronic pain can persist for 3 months or longer and lead to significant changes in a patient's personality, lifestyle, functional ability or overall quality of life (K. M. Foley, Pain, in Cecil Textbook of Medicine 100-107 (J. C. Bennett and F. Plum eds., 20th ed. 1996).
Pain has been traditionally managed by administering a non-opioid analgesic, such as acetylsalicylic acid, choline magnesium trisalicylate, acetaminophen, ibuprofen, fenoprofen, diflusinal and naproxen; or an opioid analgesic, including morphine, hydromorphone, methadone, levorphanol, fentanyl, oxycodone and oxymorphone. Id.
U.S. Pat. No. 3,238,216 to Janssen et al. discloses particular spirocompounds allegedly useful as neuroleptic, including analgesic, agents.
International Publication No. WO 99/45011 by Janssen Pharmaceutica N.V. discloses particular spirocompounds allegedly useful for the treatment of pain.
U.S. Pat. No. 6,277,991 to Hohlweg et al. discloses particular spirocompounds allegedly useful for the treatment of migraine headache.
Traditional non-opioid analgesics exert their pharmacological activity once they have passed through the blood-brain barrier. But this blood-brain barrier passage can lead to many undesirable central nervous system-mediated side effects, such as respiratory depression, increased drug-abuse potential, increased drug tolerance, increased drug dependence, constipation and unwanted euphoria.
U.S. Pat. No. 6,362,203 to Mogi et al. discloses particular 4-hydroxy-4-phenylpiperidine compounds allegedly useful as peripheral analgesic agents.
There remains a clear need in the art for new drugs useful for treating or preventing pain and that reduce or avoid one or more side effects associated with traditional therapy for treating pain.
Citation of any reference in Section 2 of this application is not to be construed as an admission that such reference is prior art to the present application.